Oil drilling causing Oklahoma quakes; what will fracking do in Nevada?

Mar. 16, 2014

US-Energy-Gas-Environment Jeff Boggs, responsible for the drilling at Consol Energy, poses in front of one of the company's Horizontal Gas Drilling Rigs exploring the Marcellus Shale outside the town of Waynesburg, Penn., on April 13, 2012. / Mladen Antonov/AFP/Getty Images

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Fracking, or drilling for oil by hydraulic fracturing, is coming to Nevada.

The Houston-based Noble Energy has 10 permits on file with the Nevada Division of Minerals for mining oil using the technique. The division holds a public hearing Monday at 10 a.m. in Carson City to review new rules for hydraulic fracturing in the state, a second Wednesday in Elko and a third Friday in Las Vegas.

The division is holding the hearing as directed by the Nevada Legislature to update its rules, said Richard Perry, minerals division administrator.

But successful use of fracking in other parts of the country has led to increased interest in eastern Nevada shale areas that were not productive using traditional oil drilling techniques, Perry said.

“We have not seen increased permitting interest, but there does seem to be increased interest in consolidating leases and land positions in eastern Nevada where these formations occur,” Perry said.

Many of the proposed rule amendments deal with water quality and the use of chemicals in the fracking process, something that has raised concerns in other places with fracking.

Modern fracking techniques were still experimental in the 1980s and 1990s, but about 10 years ago, techniques improved to where it was more practical and more economical, said James Faulds, Nevada state geologist and director of Nevada Bureau of Mines and Geology.

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Nevada’s peak oil production was in 1990 when the state produced 40 million barrels of oil in a year, Faulds said. In 2012, it was less than a tenth of that.

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But the potential looked good. In the early 1990s, Nevada’s Railroad Valley in northeastern Nye County had the oil well with the largest production of any land oil well in the lower 48 states, Faulds said.

“That kind of potential has intrigued oil companies for a couple of decades, since that was exhausted,” Faulds said.

The rocks that were the source of the Railroad Valley oil were about 300 million years old, he said. With fracking, 40 million old source rocks in northeastern Nevada look like they might yield oil. They look similar to rocks in Utah and Wyoming that produce oil.

“There’s a lot of companies and scientists looking at the results of this and whether they will find decent amounts of oil and gas in these rocks,” Faulds said.

Oklahoma earthquakes

After Oklahoma had an increase in oil production due to fracking, the area also had a surge in earthquakes.

The increase in earthquakes in Oklahoma are not because of fracking itself, but the quakes are man-made from injection of water pulled out of the ground as part of the oil extraction process, the United States Geological Survey reported on March 6.

If processes related to fracking cause increased earthquakes in Oklahoma, what will it mean for Nevada, already the second most seismically active state in the lower 48 states behind California?

Apparently little, since the processes proposed in Nevada are different than what is going on in and around Oklahoma, according to the professor who first linked Oklahoma earthquakes to the water disposal from oil wells.

But the head of the Nevada Seismology Laboratory at the University of Nevada, Reno warns geothermal exploration and energy production in Nevada could produce earthquakes as the state looks to expand its green energy production.

Hydraulic fracturing involves drilling a hole and then injecting water to force oil out of sandstone or shale formations.

Kathleen M. Keranen, an assistant professor at Cornell Universities Earth and Atmospheric Sciences Department, was the first to link a magnitude-5.6 earthquake near Prague, Okla., in 2011 to the reinjection of wastewater from oil flow back into the ground.

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Typically in oil extraction, about five barrels of water comes out for every barrel of oil pulled out, Keranen said. Newer techniques are producing hundreds to up to 1,000 barrels of water for every barrel of oil produced.

“You’re ending up with huge volumes of water to dispose of,” Keranen said. So when they reinject this wastewater — which is salty and can contain other chemicals — it can cause existing faults to move.

So what happens in a place like Nevada, where there are already lots of active faults?

“It’s a really an interesting question,” Keranen said. There has been no study done looking at the question, she said.

The geology of Nevada is different than in Oklahoma, and it doesn’t appear Noble Energy plans to do the kind of oil production that is causing problems in Oklahoma, Keranen said. Noble did not respond to request for comment.

Cody Bannister, vice president of communications for the Oklahoma Independent Petroleum Association, disputes there is evidence linking reinjection of wastewater to Oklahoma’s earthquakes.

Bannister said the water disposal rate was not higher during the resurgent oil and gas exploration than the 1980s or in the 1920s or 1930s, and there was no widespread earthquakes in prior times.

“Much of the increase has been in the area where there is not active disposal wells, especially around Arcadia Lake in central Oklahoma,” he said.

Geothermal quakes

Graham M. Kent, director of the Nevada Seismological Laboratory, said much of the discussion in his profession in the past decade has shifted from earthquakes caused by the earth’s plates mashing together and tearing apart to man-made quakes. Kent noted that geothermal exploration and production can cause earthquakes and believes pumping of geothermal fluids has caused earthquakes of up to a magnitude-2 near the Stillwater Range by Fallon.

“Obviously, one of the concerns is if you’re doing that near a fault that’s already on the edge, what’s going to happen?” Kent said.

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University of California, Santa Cruz Professor Emily Brodsky has studied geothermal energy earthquakes in California, including linking human activity and earthquakes in the Salton Sea in Southern California.

“We’ve known that geothermal power generation can create earthquakes for about 40 years,” Brodsky said. “The fact that you make earthquakes from pumping water in and out of the ground is hardly news.”

There’s still much to be learned to understand about earthquakes caused by geothermal wells, Brodsky said.

“The big question is, what is the distinction between injection wells that induce earthquakes and those that do not? Thus far, we do not have an answer to the question,” she said.

Scientists don’t know if it is related to the volume of water being used, the geology of the area, the stress on earthquake faults or something else. With enough knowledge, they could do a better job of limiting earthquakes.

“We don’t know how to engineer them properly,” Brodsky said. “That is a difficult and frustrating place to be for everybody.”

Both Brodsky and Kent said scientists could be greatly helped in understanding geothermal well earthquakes by knowing how much water and pumped in or out and when.

Brodsky said she was able to do her Salton Sea study because California requires more data reporting than most other places.

“As a scientist, what we need is gallons of fluid in and out of the ground every day and where exactly it went.” Brodsky said. “There are a lot of scientists who would really like to study this problem. ... I see some earthquakes, I see some wells, and I don’t know if they are related without more information.”

“We just want better monitoring around the geothermal systems in Nevada,” Kent said. “And if we have wastewater sites or fracking in Nevada, we just kind of want to sense the pulse, to get a better sense of how the seismicity is evolving through time.”